1. Field
Aspects of embodiments of the present invention relate to a cap assembly for a secondary battery and a secondary battery including the same.
2. Description of the Related Art
Secondary batteries are rechargeable and, thus, may be repeatedly used as energy sources of, for example, portable electronic devices, electric tools, gardening tools, electric vehicles (EVs), electric power storage systems, etc.
Generally, cylindrical secondary batteries are used in such applications, and current interrupt devices (CIDs) are provided in such cylindrical secondary batteries to ensure safe operation of the cylindrical secondary batteries.
CIDs are protection devices for preventing explosions caused by high internal pressure situations arising in secondary batteries. When the internal pressure of a secondary battery increases, the CID interrupts current (e.g., current flow) between an electrode assembly and a cap assembly of the secondary battery to stop charging/discharging of the secondary battery.
However, if an insulator of such a CID melts due to generated heat, for example, in a short-circuit situation, the current may not be interrupted by the CID.
For example, when a positive electrode plate and a negative electrode plate of a secondary battery are short-circuited, an abnormal situation may arise due to heat (e.g., joule heat) caused by a short-circuit current, and if an insulator of a CID of the secondary battery melts due to the heat, the current flowing from the electrode assembly to the cap assembly may not be interrupted. As a result, the secondary battery may be overcharged and may catch fire and/or explode.